Attachment-plug fitting.



G. B. THON/IAS.1 ATTACHMENT PLUG FITTING.

APPucAloN msu APR. zo. 1916K .Patented Apr., 23, 1918.

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GJB. THOMAS. ATTACHMENTPLUG FITTING. APPLlC-ATION 'FILED APR. 20. \9l6.

Patented Apr. 23, 1918.

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.. ...al np GERGE B. THOMAS, F IBRTIDGEPORT, CONNECTICUT, SSGNOR T0 THE BJBFZ'ANT ELEC- 0F FRTJDGEPURT, CUNNETTC'UT, .d CRATION 0F CONNECTICUT.

TTACJEIMJENT-IPLUG FTTTING.

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Specification of Letters Patent.

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To all 'whom 'it may concern: Be it lrnown that ll, GEORGE B. THOMAS, a citizen of the United States of America, and residing at Bridgeport, in the county ot Fairfield and State of Connecticut, have invented a certain new and useful llmprove ment in Attachment-Plug Fittings, of which the following is a specification.

My invention `relates to attachment plug fittings and the object of my invention is to provide means whereby a standard type ot receptacle may be furnished with a barrier element which serves to convert the receptacle intoa polarized tting, should it be desired to incorporate this feature therein.

Referring to the accompanying drawings, Figure 1 is a perspective of the receptacle and plug in vwhich my invention is embodied in one form;

Fig. 2 is an inverted plan of the plug element; v

Fig. 3 is a detached perspective of one ot the receptacle terminals and the polarizing element associated therewith;

face plate and plug removed;

Fig. 5 is a section on the line 5-f5, Fig. l. Fig. 6 is a perspective of a receptacle and plug of heavier capacity in which my invention is embodied in di'erent form;

Fig. 7 is a plan of this receptacle with face plate removed;

Fig. 8 is an inverted ment; and

Fig. 9 is a longitudinal section on the line 9 9, Fig. 7, s iowing the plug inserted but partially broken away to disclosethe barrier.

lln many installations of attachment plug :fittings it is immaterial whether or not the engaging contacts of the plug and receptacle be polarized. 0n the other hand, there are trequently'occasions in which it is desirable that the plug and receptacle should be polarized so that the current shall alwaysA pass in the same direction through the implement energized bythecurrent. ]l am vaware that'means have been heretofore provided by which such polarization has been accomplished, but so far as ll am aware such means have been permanently associated with the parts and form an integral or fixed part of the appliance and are such that neither element ot the litting can be employed as a non -polarized device. The presplan of the plug `ele-` u ent invention provides a barrier which may be installed in a standard non-polarized receptacle to polarize the same.

ln the construction shown in Figs. 1 to 5, the present device comprises a receptacle 10 ot the type shown in the Goodridge Patent 1,166,349 having a cup-shaped insulating body' normally protected by a cover plate 11 with doors 12 opening to the receptacle chamber, and being secured to the face plate by means ot supporting ears 13 into which take countersunk securing screws 14: ypassing through the cover plate 11. The wirel terminal straps 15 extend from diagonally opposite .corners of the receptacle chamber to the studs 16 which project upwardly through the insulating lining 17 and `coperate with -the contacts 18 carried by the plug 19. lln the form shown in the Goodridge patent these contacts 18 are so arranged with relation to the stud 16 that they engage the same whether the plug is reversed in position or not. lln other words, the itting is' not polarized. Fig. l is a plan of the receptacle with the ll have now provided a barrier 20 in the torno of an angled strap, the base of which underlies one ot the studs '16 and is held in position by means of the securing screw 21. rlhe latter passes up through the bottom of the receptacle body the strap 15, base of the barrier and threads into the tapped bore of the stud 16, so that the base of the barrier is clamped between the strap 15 and the stud 16. To receive this barrier and permitthe insertion o1 the plug 19, l provide a channel 200 on one side of the entering end ot the plug. llt is obvious that when the plug is inserted in such position that the barrier 20 and channel 200 register, the plug may be inserted, whereas when the plug is reversed, the barrier 20 engages the body of the plug on the opposite side and prevents its entry into the receptacle.

lln the torm shown in Figs. 6 to 9 a receptacle of the same general construction, but ot larger capacity, is shown. lln this form the barrier comprises a supplemental block ot insulation 22 which is secured in position between the receptacle studs 16 by means of a securing screw 23 passing through the base.

Patented dpr. 23, 191.

The attachment plug 24 has a recess 25 formed .Y in its entering end which receives the barrier lllll will engage the end of the plug and prevent its entry into the receptacle a suliicient distance to establish contact between the terminals of the tacle.

The constructions described both permit the standard non-polarized receptacles to be rendered polarized by the mere addition of the independent barrier elements 20 or 22. The coperating attachmentplugs 19 and 24 are always provided with their recesses 200 or 25 since this in no way interferes with their utility when the receptacle is nonpolarized and renders them lit for coperation with the barriers if the receptacle has been converted into a polarized fitting by the addition of the barrier element.

Various other ways of accomplishing the same result will readily occur to those skilled in the art which do not depart from what I claim as my invention.

I claim as my invention 1. An attachment plug receptacle having an insulating body and receptacle terminals plug and those of the recepf mounted thereon, in combination with an independent barrier `element and vmeans for `detachably securing the same within the receptacle to polarize the same, said barrier being arranged in position to prevent nonpolarized engagement of the coperating contacts on the plug and receptacle, respectively. a

2. An attachment plug receptacle having an insulating body and receptacle terminals mounted thereon, in combination with an independent barrier element and means for detachably securing the same within the receptacle to polarize the same, together with an attachment plug having a channel adapted to receive said barrier when the plug is inserted in predetermined polarized relation to the terminals of the receptacle.

3. An attachment plug receptacle having a chambered, insulating body, wire terminals mounted at opposite ends of the receptacle, plug-receiving terminals within the chamber and straps extending thereto from the wire terminals, an insulating lining overlyin said straps and extending upward beyond t e wire terminals to guard against the entry of wire beards into the chamber, and an independent barrier element mounted on the base of the chamber and passing upward through said lining into the path of an entering plug, and adapted to prevent the insertion of the latter save in polarized relation to the terminals of the receptacle.

4. An attachment plug receptacle having a chambered insulating body, receptacle terminals upstanding from the base of the chamber together with a readily detachable barrier upstanding from said base and projecting into the path of a non-polarized plug to prevent the engagement of its terminals with those of the receptacle.

5. An attachment plug receptacle having an insulating body, receptacle terminals mounted therein and adapted to coperate with the contacts of a non-polarized plug, in combination with a barrier device and means for optionally securing the same in the receptacle to polarize the same.

In testimony whereof I have signed my name to this specication, in the presence of two subscribing witnesses.

GEORGE B. THOMAS.

Witnesses:

G. W. GooDRIDGE, H. M. WIcHmi'r. 

